Modification of the Elastic Recovery Test and its Relationship to Performance Related Properties of Modified Asphalt Binders

摘要

Elastic recovery is implemented by many state agencies to complement the grading system formodified binders. The current ASTM/AASHTO standards for elastic recovery utilize theductility bath as the measurement apparatus. These procedures are time consuming, notautomated, and user sensitive. This paper introduces a simplified method for measuring theelastic recovery in the Dynamic Shear Rheometer. The newly developed proceduremeasurements correlate very well with the current procedure (R~2=97%). The procedure wasinitially proposed with 60 minutes relaxation time; however, statistical analysis revealed that 30minutes is sufficient. Twenty two binders, both neat and modified, were tested with using thenew procedure. The results were compared with Multiple Stress Creep and Recovery test results(MSCR) and fatigue resistance properties collected from: time sweep test, binder yield energytest (BYET) and linear amplitude strain. The results indicate that some correlation existsbetween ER-DSR and certain binder fatigue properties. The new procedure is recommended toreplace the current ductility bath standard elastic recovery test. It is also recommended that stateagencies consider the new proposed MSCR and Binder Fatigue tests as they represent directmeasure of damage resistance characteristics.